scholarly journals Lithology Effect On Total Organic Content, Maturity Level And Depositional Environment Of Pemaluan Formation as a Shale Gas Bearing Formation, Kutai Basin, East Kalimantan

2019 ◽  
Vol 1363 ◽  
pp. 012039
Author(s):  
N Novelyarisyanti ◽  
Y Iskandar
Keyword(s):  
Shale Gas ◽  
Depositional Environment ◽  
Organic Content ◽  
Maturity Level ◽  
East Kalimantan ◽  
Total Organic Content ◽  
Gas Bearing

scholarly journals SHALE GAS SWEET SPOT POTENTIAL OF TUNGKAL GRABEN, JAMBI SUB-BASIN SOUTH SUMATERA BASIN

2019 ◽  
Vol 42 (3) ◽  
pp. 109-114
Author(s):  
Taufik Ramli ◽  
M. Heri Hermiyanto Z ◽  
Andy Setyo Wibowo
Keyword(s):  
Shale Gas ◽  
Organic Geochemistry ◽  
Primary Source ◽  
Organic Content ◽  
Source Rocks ◽  
Sweet Spot ◽  
Gas Generation ◽  
Spot Area ◽  
Total Potential ◽  
Gas Bearing

The Tungkal Graben is located in Jambi Sub-basin, the northern part of South Sumatera Basin. This basin is known as one of the largest hydrocarbons producing basin in Indonesia. There are several proven source rocks in the South Sumatera Basin. The paralic shales and coal horizon of Talangakar Formation (TAF) are known as primary source rock in this basin and considered as a reservoir of shale gas-bearing in Tungkal Graben Area as well. This study used surface geological data that was collected from the southern foot of Tiga Puluh Mountain as the outcrop analogy and subsurface data (existing well and seismic data) in Tungkal Graben Area. This study applied integrated methods including environmental deposition analysis, organic geochemistry analysis, petrophysical analysis, seismic interpretation, sweet spot delineation, and volumetric of gas in place (GIP) calculation. TAF observed both on the outcrop and well is transition deposit that consists of the dominance of shale and siltstone with interbedded of coal, sandstone, and limestone. Shale and siltstone of TAF have characteristic which is appropriate as a shale gas bearing, with sufficient organic content richness, suitable kerogen type, its maturity entering the early gas generation and proper brittleness index (BI). The sweet spot area is an area that has met the criteria for potential shale gas and determined by pay zone criteria. Depend on the criteria, Net to gross for shale gas is 0.158, early gas generation estimated at a depth of 10250 feet, and sweet spot area reaches 8.9 x 108 ft2. Thus, the total potential of shale gas resources from the calculation using the Ambrose method is 2.12 TCF.

Prospects and Challenges of Developing Unconventional Petroleum Resources in the Anambra Inland Basin of Nigeria

2016 ◽  
Author(s):  
K. Mosto Onuoha ◽  
Chidozie I. Dim
Keyword(s):  
Shale Gas ◽  
Oil And Gas ◽  
Petroleum Industry ◽  
Organic Content ◽  
Shale Oil ◽  
Thermal Maturity ◽  
Total Organic Content ◽  
Anambra Basin ◽  
Petroleum Resources ◽  
Oil And Gas Resources

ABSTRACT The boom in the development of unconventional petroleum resources, particularly shale gas in the United States of America during the last decade has had far reaching implications for energy markets across the world and particularly for Nigeria, a country that traditionally has been Africa’s leading crude oil producer and exporter. The Cretaceous Anambra Basin is currently the only inland basin in Nigeria where the existence of commercial quantities of oil and gas has been proven (outside the Tertiary Niger Delta Basin). The possibility of similarly finding commercially viable resources of unconventional petroleum resources in the basin appears quite attractive on the basis of the existence of seepages of shale oil and presence of coal-bed methane in some of the coal seams of the Mamu Formation (Lower Coal Measures) in the basin. This paper presents the results of our preliminary assessment of the shale oil and gas resources of the Anambra Basin. Our main objective is to locate the zones of very high quality plays within the basin, focusing on their depositional environments (whether marine or non-marine), areal extent of the target shale formations, gross shale intervals, total organic content, and thermal maturity. Data on the total organic content (TOC %, by weight) and thermal maturity of shales from different wells in the basin show that many of the shales have high TOCs (i.e greater than 2%) comparable to known shale gas and shale oil plays globally. Shale oil seepages are known to occur around Lokpanta in south-eastern Nigeria, but there is a general predominance of gas-prone facies in our inland basins indicating good prospects for finding unconventional petroleum in this and other Nigerian inland sedimentary basins. The main challenge to the exploration of unconventional resources in Nigeria today has to do with the absence of the enabling laws and regulatory framework governing their exploration and subsequent exploitation. The revised Petroleum Industry Bill (PIB) currently under consideration in the National Assembly is expected to introduce drastic and lasting changes in the way the petroleum industry business is conducted in the country, but all the provisions of the draft law pertain mainly to conventional oil and gas resources.

Seismic expression of delta to deep-lake transition and its control on lithology, total organic content, brittleness, and shale-gas sweet spots in Triassic Yanchang Formation, southern Ordos Basin, China

2017 ◽  
Vol 5 (2) ◽  
pp. SF1-SF14 ◽  
Author(s):  
Hongliu Zeng ◽  
Wei Wang ◽  
Quansheng Liang
Keyword(s):  
Shale Gas ◽  
Hot Spot ◽  
Ordos Basin ◽  
Analysis Data ◽  
Seismic Attributes ◽  
Organic Content ◽  
Tunnel Effect ◽  
Yanchang Formation ◽  
Total Organic Content ◽  
Sweet Spots

The Triassic Yanchang Formation is currently a hot spot for lacustrine shale-gas exploration in the Ordos Basin, China. A seismic-sedimentological study using a newly acquired 3D survey was conducted to advance the interpretation and prediction of the shale-gas reservoirs. The seismic volume was converted into a log-lithology volume at the thin-bed level. The inverted acoustic impedance volume was stratal sliced to extract seismic geomorphologic information. Deltaic facies and depositional history were interpreted using lithologic and planform morphology of seismic attributes on stratal slices. Detailed core analysis data including total organic content (TOC), mineral composition, and mechanical properties of sandstones and shales were correlated with seismic-derived lithology and facies. Microseismic data were evaluated for reservoir performance in production wells. Finally, shale-gas sweet spots, or optimal drilling targets, were predicted by mapping relatively high-brittleness lithofacies in 3D using seismic attributes. In the three submembers of the Chang 7 member of the Yanchang Formation, the high-TOC Ch7-1 shale unit is not ideal for shale-gas development because of its ductile nature and tunnel effect when fracturing. Ch7-2 prodelta sediments are shale-gas sweet spots because they are thick, relatively brittle, and in close proximity to high-TOC Ch7-1.

scholarly journals Effect of reservoir pressure and total organic content on adsorbed gas production in shale reservoirs: a numerical modelling study

2022 ◽  
Vol 15 (2) ◽  
Author(s):  
Moataz Mansi ◽  
Mohamed Almobarak ◽  
Christopher Lagat ◽  
Quan Xie
Keyword(s):  
Numerical Modelling ◽  
Shale Gas ◽  
Organic Content ◽  
Gas Production ◽  
Reservoir Pressure ◽  
Adsorbed Gas ◽  
Total Organic Content ◽  
Simulation Results ◽  
Shale Reservoirs ◽  
The Impact

AbstractAdsorbed gas plays a key role in organic-rich shale gas production due to its potential to contribute up to 60% of the total gas production. The amount of gas potentially adsorbed on organic-rich shale is controlled by thermal maturity, total organic content (TOC), and reservoir pressure. Whilst those factors have been extensively studied in literature, the factors governing desorption behaviour have not been elucidated, presenting a substantial impediment in managing and predicting the performance of shale gas reservoirs. Therefore, in this paper, a simulation study was carried out to examine the effect of reservoir depth and TOC on the contribution of adsorbed gas to shale gas production. The multi-porosity and multi-permeability model, hydraulic fractures, and local grid refinements were incorporated in the numerical modelling to simulate gas storage and transient behaviour within matrix and fracture regions. The model was then calibrated using core data analysis from literature for Barnett shales. Sensitivity analysis was performed on a range of reservoir depth and TOC to quantify and investigate the contribution of adsorbed gas to total gas production. The simulation results show the contribution of adsorbed gas to shale gas production decreases with increasing reservoir depth regardless of TOC. In contrast, the contribution increases with increasing TOC. However, the impact of TOC on the contribution of adsorbed gas production becomes minor with increasing reservoir depth (pressure). Moreover, the results suggest that adsorbed gas may contribute up to 26% of the total gas production in shallow (below 4,000 feet) shale plays. These study findings highlight the importance of Langmuir isothermal behaviour in shallow shale plays and enhance understanding of desorption behaviour in shale reservoirs; they offer significant contributions to reaching the target of net-zero CO2 emissions for energy transitions by exhibiting insights in the application of enhanced shale gas recovery and CO2 sequestration — in particular, the simulation results suggest that CO2 injection into shallow shale reservoirs rich in TOC, would give a much better performance to unlock the adsorbed gas and sequestrate CO2 compared to deep shales.

Solidifying Mud Cake to Improve Cementing Quality of Shale Gas Well: A Case Study

2015 ◽  
Vol 8 (1) ◽  
pp. 149-154 ◽  
Author(s):  
Jun Gu ◽  
Ju Huang ◽  
Su Zhang ◽  
Xinzhong Hu ◽  
Hangxiang Gao ◽  
...  
Keyword(s):  
Shale Gas ◽  
Calcium Silicate Hydrate ◽  
Drilling Fluid ◽  
Cement Slurry ◽  
Gas Well ◽  
Safety Requirements ◽  
Mud Cake ◽  
Gas Bearing

The purpose of this study is to improve the cementing quality of shale gas well by mud cake solidification, as well as to provide the better annular isolation for its hydraulic fracturing development. Based on the self-established experimental method and API RP 10, the effects of mud cake solidifiers on the shear strength at cement-interlayer interface (SSCFI) were evaluated. After curing for 3, 7, 15 and 30 days, SSCFI was remarkably improved by 629.03%, 222.37%, 241.43% and 273.33%, respectively, compared with the original technology. Moreover, the compatibility among the mud cake solidifier, cement slurry, drilling fluid and prepad fluid meets the safety requirements for cementing operation. An application example in a shale gas well (Yuanye HF-1) was also presented. The high quality ratio of cementing quality is 93.49% of the whole well section, while the unqualified ratio of adjacent well (Yuanba 9) is 84.46%. Moreover, the cementing quality of six gas-bearing reservoirs is high. This paper also discussed the mechanism of mud cake solidification. The reactions among H3AlO42- and H3SiO4- from alkali-dissolved reaction, Na+ and H3SiO4- in the mud cake solidifiers, and Ca2+ and OH- from cement slurry form the natrolite and calcium silicate hydrate (C-S-H) with different silicate-calcium ratio. Based on these, SSCFI and cementing quality were improved.

Comprehensive Analysis of Production Loggings in Fuling Shale Gas Play in China

2021 ◽  
Author(s):  
Yaowen Liu ◽  
Wei Pang ◽  
Jincai Shen ◽  
Ying Mi
Keyword(s):  
Shale Gas ◽  
Mineral Content ◽  
Horizontal Wells ◽  
Organic Content ◽  
Gas Production ◽  
Liquid Loading ◽  
Comprehensive Overview ◽  
Gas Field ◽  
Well Trajectory ◽  
Positive Effect

Abstract Fuling shale gas field is one of the most successful shale gas play in China. Production logging is one of the vital technologies to evaluate the shale gas contribution in different stages and different clusters. Production logging has been conducted in over 40 wells and most of the operations are successful and good results have been observed. Some previous studies have unveiled one or several wells production logging results in Fuling shale gas play. But production logging results show huge difference between different wells. In order to get better understanding of the results, a comprehensive overview is carried out. The effect of lithology layers, TOC (total organic content), porosity, brittle mineral content, well trajectory is analyzed. Results show that the production logging result is consistent with the geology understanding, and fractures in the favorable layers make more gas contribution. Rate contribution shows positive correlation with TOC, the higher the TOC, the greater the rate contribution per stage. For wells with higher TOC, the rate contribution difference per stage is relatively smaller, but for wells with lower TOC, it shows huge rate contribution variation, fracture stages with TOC lower than 2% contribute very little, and there exist one or several dominant fractures which contributes most gas rate. Porosity and brittle minerals also show positive effect on rate contribution. The gas rate contribution per fracture stage increases with the increase of porosity and brittle minerals. The gas contribution of the front half lateral and that of latter half lateral are relatively close for the "upward" or horizontal wells. However, for the "downward" wells, the latter half lateral contribute much more gas than the front half lateral. It is believed that the liquid loading in the toe parts reduced the gas contribution in the front half lateral. The overview research is important to get a compressive understanding of production logging and different fractures’ contribution in shale gas production. It is also useful to guide the design of horizontal laterals and fractures scenarios design.

Sign in / Sign up

Export Citation Format

Share Document